Believe it or not, I actually liked speeches. But here's my few cents of advice
- have an interesting introduction. At least your audience, and your marker, won't go to sleep in the first 10 seconds of your presentation, and they'll take you more seriously than a person who starts with "good morning. Romeo and Juliet was a great play about (insert some reference to question here)"
*one of the stages where it's alright to have colloquial language. Another place: conclusion/some other nice wrap up that links to your intro ideas
- don't start with good morning. You're wasting your time.
- use inflexions when you talk. Again it's more interesting.
- avoid long sentences. Tend to shorter ones,with many connecting sentences between ideas, so that your audience can follow on.
- it's a speech not an essay. Hence, in my opinion, it should be interesting to be read out, so yeah I guess your language can be a little colloquial at times, but overall formal.
* but in saying that, you got to follow that marking guideline, and if they give no marks for presentation, well, ignore the above and write an essay.
^ and another addition, make sure you have enough textual evidence and shit there. I bet I lost that one mark (from 100%) every time because there "wasn't enough" even though it was a perfectly paced 5 minute speech.